The invention relates to the technical field of driving assistance for automobile vehicles, and more particularly, assistance for the avoidance of obstacles.
Accidents by unintentionally straying from a traffic lane, due to the lack of attention of the driver, continue to represent a significant fraction of road traffic accidents. Equipped with active safety means, some vehicles are capable of evaluating their path and of recognizing the environment in order to determine a measurement of risk associated with the situation. Actions may then be undertaken, automatically or shared with the driver, in order to keep the vehicle within its traffic lane for cases of lack of attention of the driver, of falling asleep or of feeling unwell. This is the active safety function “Lane Keeping Assistance” (LKA) or “Lane Departure Avoidance” (LDA).
Until now, the decision for activation of such a driving assistance system only took into account a possible departure from the traffic lane.
From the prior art, the following documents are known dealing with the problem of side or front collision avoidance when the vehicle leaves its traffic lane.
The documents EP1790542 (Nissan Motors), KR100851120 (Hyundai Motor) and U.S. Pat. No. 7,580,785B2 (Nissan Motor) describe applications of the type “Lane Departure Avoidance” or “Lane Keeping Assist”
In this type of application, the lane markings are detected and an intervention by steering the wheels or by differential braking is undertaken in order to avoid the departure from the lane. However, in these documents, lateral obstacles are not taken into account.
The documents EP 2 288 533 B1, EP 1 726 481 B1, U.S. Pat. No. 8,111,147 B2, and GB (11)2512317 (13)A 2 describe applications of type “Blind Spot Intervention” or “Lane Change Assist”. In this type of application, the desire of the driver to change lane is determined through the activation of the indicators, and it is estimated whether the maneuver is dangerous by determining whether a vehicle is present in a blind spot, or is approaching with a high relative speed. In such a case, a path correction is carried out through steering or differential braking. In these documents, the fixed lateral obstacles are not taken into account. Furthermore, the objective is only to assist the driver in the case of an intentional change of lane and not to intervene when there is an unintentional departure from the traffic lane.
In the preceding applications, the notion of a system for avoidance of an unintentional departure from a lane, taking the true dangers of lateral collision into account, does not exist.
There accordingly exists a need for a system for controlling the steering means of the vehicle in the case of imminent collision taking lateral obstacles into account in an effective manner and operating in a transparent manner for the driver.
Indeed, activations that are too frequent may annoy the driver and cause him/her to disable the function, which reduces its efficacy for preventing accidents.
Moreover, in some situations, the lane that is navigable in complete safety narrows all the more if there are obstacles on the side of the road. For example, the risk for the vehicle when a white/yellow line is crossed is different if, beyond the latter, the road surface comprises 80 cm of tarmac or if the road surface only comprises 20 cm of tarmac followed by a ditch or by a safety barrier.